Osteotomy is a surgical procedure which involves cutting and removing a section of bone. The procedure is used to correct many types of bone deformities found in the human leg. For example, in the instance of improper leg formation during growth, undesired angulation or orientation of a particular bone with respect to other bones of the leg often occurs such as the condition referred to as bowleggedness the surgical procedure for overcoming this type of medical problem normally involves the removal of a wedge-shaped section of the knee portion of the malformed or misaligned leg at a predetermined location which causes the relative repositioning of the remaining bone sections of the leg so as to impart to the surgically corrected leg the proper relative configuration or orientation. The wedge-shaped section removed from the original knee bone is, of course, of a predetermined size which naturally depends upon extent of the correction required. For example, by known techniques, an orthopedic surgeon can determine the extent of leg deformity and the required amount of a wedge that is needed to correct the leg deformity.
To make the correct adjustment to the leg requires not only cutting out the correctly sized bone wedge portion at a proper angle, but also assuring that there remains, at the apex of the wedge, residual bone of sufficient thickness to prevent a complete severance or fracture of the bone and to promote mending together of the cut or bone portions. Also, to ensure correct realignment of the bone, it is essential that the cuts into the bone, performed to remove the wedge-shaped segment, be substantially smooth and planar so that, when the severed end regions of portions of the remaining bone segments are brought into contact their surfaces mate uniformly across the entire severed surfaces to promote rapid and structurally effective mending of the cut bone portion. Furthermore, to assure this rapid mending, often times a suitably shaped blade plate or side plate is coupled, by screws, to the remaining bone segments, after removal of the wedge portion, and is used to hold the segments together. To properly use such a blade plate this requires that the removed wedge portion have a right angle configuration.
U.S. Pat. No. 4,335,715 issued Jun. 22, 1982 to W. H. Kirkley or "Osteotomy Guide" discloses an apparatus in which a pair of pins positioned on an arcuate track are inserted into the bone to serve as a guide for the surgeon in making cuts into the bone. The device has no means for determining the apex of the wedge. Therefore, the surgeon must rely on his judgment to determine the apex or remove an entire wedge without leaving any residual bone. Obviously, such a procedure complicates the healing process.
U.S. Pat. No. 4,349,018, issued Sept. 14, 1982 to G. R. Chambers for "Osteotomy Apparatus" discloses a fairly complex and cumbersome device for guiding saw cuts in a operation for the total removal of the Knee. Because of the device's complexity it is ill suited for simpler osteotomy procedures.
U.S. Pat. No. 4,627,425, issued Dec. 9, 1986 to H. W. Reese for "Osteotomy Appliances and Method" discloses a guide to be used by the surgeon to make a second cut in a bone at a predetermined angle from a first cut. To locate the apex of the wedge, a pin has to be inserted vertically into the bone. Also, the device produces a wedge without a right angle and therefore cannot be used with the blade plate or side plate described above.
U.S. Pat. No. 4,757,810, issued Jul. 19, 1988 to H. W. Reese for "Osteotomy Apparatus and Method" discloses a guide for precisely locating two parallel, spaced apart bone cuts. This guide however cannot be used to cut a wedge from the bone.
Still there is a need for a osteotomy guide that would allow a surgeon to remove a pre-calculated sized bone wedge having a right angle, that would leave a sufficient amount of residual bone and that does not require drilling a vertical pin into the bone to locate the apex of the wedge.